Endosonographic T-staging of esophageal carcinoma: A learning curve

Background:lt has been suggested that 50 endosonographic examinations are necessary to attain sufficient skill to become accurate in the staging of esophageal carcinoma. Methods: Since July 1991 all esophageal endosonographies have been performed by one investigator. The database, containing all examinations since July 1991, was reviewed to investigate the presence of a learning curve in T-staging of esophageal carcinoma by comparing the endosonographic T-stage with the pathologic T-stage. Results: From July 1991 until April 1993, 231 endosonographies were performed for esophageal malignancies. Eighty-nine patients had been referred for preoperative staging and underwent surgical exploration. Seventy-one tumors were resected. The patients were split in two groups. Group I consisted of 36 patients examined between July 1991 and April 1992. In this period 100 endosonographies were performed. Group II consisted of 35 patients examined between April 1992 and March 1993. In this period 131 endosonographies were performed. Overall endosonographic T-staging was correct in 70%. The accuracy in group I was 58%; in group II 83% (p < 0.05). Overstaging was equally common in groups I and II (14%). Understaging was common in group I (28%), but rare in group II (3%). Conclusion: This study shows a definite learning curve for endosonographic T-staging of esophageal carcinoma. Acceptable accuracy rates could only be achieved after 100 examinations.